This innovative, ghostlike structure is a wind dam, a sail-like structure to harness wind energy, and thought to be the first of its kind in the world. If the project is given the green light, the $5 million dam, which is designed by British architect Laurie Chetwood, will be going up next year on Lake Ladoga, in the northwest of Russia. More pics and details below.

The dam consists of a spinnaker sail, similar to the mainsail of a yacht, which captures the wind, funneling it through a turbine and generating energy. Measuring 75 meters wide and 25 meters high, the dam may be joined by a second one in a gorge further up the valley.

Mr Chetwood, the dam's creator, thinks that the sail looks like a bird dipping its beak into the water. "It will be much less of a blot on this beautiful and unblemished landscape," he claims, adding that the sail will be more effective than other methods of harvesting energy. "It replicates the work of a dam and doesn't let the wind escape in the way it does using traditional propellers." [Building Design via Dezeen]